1. Field of the Invention
The present invention relates to a torquing or wrenching arrangement for the installing and tightening of screws at a high torque.
2. Discussion of the Prior Art
A wrenching arrangement of that type has been disclosed in U.S. Pat. No. 2,212,696. This earlier wrenching arrangement utilizes a so-called straight wrench which is attached to the lower end of a telescope support strut whereby the screw axis extends parallel to the longitudinal axis of the telescope support strut. This causes the reaction torque of the wrench to be transferred to the telescope support strut as a torsional moment or torque relative to the longitudinal axis of the telescope support strut. In order to absorb the torsional torque, the telescope support strut is imparted a multiple-edged section, as shown in FIG. 3 of the drawing of the patent. The primary drawback of this prior art device lies in that the reaction torque or moment of the wrench must be transferred as torsional moment over the entire length of the telescope support strut, so that the telescope support strut must of necessity exhibit an accordingly high resistance to torsion, which causes the telescope support strut to assume an undesirably heavy construction.
Heretofore, screws requiring a high installation torque were tightened with so-called striker-power wrenches. Due to the striking movement of these tools during the tightening of the screws, a relatively small amount of torque is sufficient for tightening the screw, so that the above-described manner of attaching the striker-type power wrench to a telescope support strut is still feasible, considering the resistance of the telescope support strut to torsion. Striker-type power wrenches are nevertheless subject to the considerable disadvantage in that the striking movement generates extensive noise, particularly when the screws must be installed in large, metal elements acting as resonant bodies. Such large metal elements are, for instance, chassis for trucks. Inasmuch as during the manufacture of such large element several screws must be tightened simultaneously, the noise generated by this tool often increases to a level where it becomes a health hazard.